What I mean is, if my friend and I look at a red object, our brains
interpret the colour as red. But he could be looking at a colour which my
brain would have called green.
To take it further, how do we know that everybody in the world sees the
same things as everybody else? After all, we cannot look into another
person's brain and tell if what he sees is exactly what I see.
I hope I'm making sense here. Thanks.